> Read their terms.
There are no such terms. In a comment further in this thread, you linked to inaccurate posts from an anonymous user on the Privacy Guides forum as your sources.
> They still run everything through Google services.
No, this is completely untrue. GrapheneOS doesn't have any mandatory connections in the first place.
> They are essentially a man in the middle to Google services.
No, GrapheneOS is a privacy and security hardened mobile OS. It isn't a proxy service and doesn't have any mandatory services. It does not come with Google Play services.
> I read their terms to mean that they could snarf everything that every graphene device would normally send to Google because they are "anonymizing it" before sending it to Google.
There are no such terms despite what's claimed in the incorrect anonymous posts you read.
> What we need is Android like Lineage that works on more devices than Pixels and simply have it without Google services at all.
GrapheneOS doesn't add a single Google service compared to the Android Open Source Project (AOSP). It replaces all of the standard AOSP default connections with our own servers by default. It also adds settings to control each of the connections. These settings mostly have a choice between GrapheneOS server, Standard (Google) server or Off.
LineageOS doesn't provide replacements for the Google services pr toggles for user control. This is covered in the third party comparison at https://eylenburg.github.io/android_comparison.htm which provides an overview of what's done with most of the default AOSP connections. The table doesn't cover all the standard connections, but GrapheneOS does deal with all of them by replacing the standard servers and provides settings to control the connections.
We add opt-in services for geocoding and network-based location as an alternative to the Google service. We host geocoding ourselves with Nominatim using the standard OpenStreetMap, Wikipedia and other supplementary data. Our network-based location service has a choice between Apple or our proxy to Apple but we plan to build our own database to host it directly.
SUPL which is a limited form of network-based location has a choice between our proxy to Google, Google or Off. SUPL can be fully replaced by enabling network-based location and leaving the default enabled static global PSDS database downloads enabled. We'll be hosting our own SUPL server using our network-based location database once the much easier to build subset of the database for cellular towers is ready for use.
Google certified devices use Google's hardware key attestation root and service so supporting that inherently has to use either a proxy (our default) or their server including for a non-Android-based OS running on the same hardware which wants hardware attestation support to be functional. That's tied to the hardware ecosystem based on certification, not software. Non-Google-certified devices will use a different service for attestation key provisioning, either hosted by GrapheneOS or a proxy to the service by the hardware provider or certification authority.